Radiating tuned inductance coil antenna



1968 c. l. PETERS, JR 3,412,403

RADIAIING TUNED INDUCTANCE COIL ANTENNA Filed Dec. 22, 1964 INVENTOR.CAR! I. PETERS Ja.

ATTORNEY.

United States Patent 0 3,412,403 RADIATING TUNED INDUCTANCE COIL ANTENNACarl I. Peters, Ira, 307-A Fowler Ave., China Lake, Calif. 93555 FiledDec. 22, 1964, Ser. No. 420,373 1 Claim. (Cl. 343748) ABSTRACT OF THEDISCLOSURE This invention defines a novel antenna utilizing an inductorof a predetermined number of turns in which one or a group of more thanone of these turns are shunted by a capacitor which may be variable andan R-F meter being in series with the capacitor in one embodimentthereof.

The main purpose of this invention is to radiate radio frequency energyusing a transformation technique by which a few turns of an inductancebecomes the radiation element. Heretofore the usual method has been theconstruction of a wire or steel array having mechanical dimensionsdirectly related to the desired operating frequency. This method has thedisadvantage that when once constructed the array responds to only onefrequency unless mechanical modifications or adjustments are made. Inthe broadcast band such towers are very tall and constitute a hazard toair navigation. In military use it is often desirable to have oneantenna perform on more than one frequency. In order to do this it isnecessary to use matching systems.

It is, therefore, the general purpose and objective of this invention toprovide a novel antenna for the propagation of the radiant energy havingbut two major components and capable of operating at high efficiency.

A more specific object of the invention is to provide an antenna of thecharacter described that can be readily tuned for operation at differentfrequencies.

Another object of the invention is to provide a novel circuit formatching the transmission line characteristic output impedance into avalue of one ohm or less, whereby in the transformation the circuit willradiate and act as an antenna.

Other objects and advantages will appear and be brought out more fullyin the following specification, reference being had to the accompanyingdrawing.

In the drawing the figure shows in diagrammatic form a preferredembodiment of this invention.

In the drawing the numeral 1 indicates generally a coaxial cable orother transmission line, the terminals of which are connected to theends of an inductance coil 2. This coil has a pair of variable tapswhich are connected through an ammeter 3 to a variable condenser 4. Theassembly is mounted on a non-conductive material, and when finallyadjusted, covered with a non-magnetic weather cover. It will be observedthat the connections of the condenser to the coil are held at aboveground potential.

In the operation of the invention the radio frequency energy impressedacross the inductance, and the two taps 3,412,403 Patented Nov. 19, 1968to the condenser will couple some of this energy into the condenser. Inthis circuit it will be noted that the inductance 2 comprises only aportion of the load that the source energy sees, by the transformationas to where the taps 5 are positioned and the resonant conditionrepresented by the L of the coil and the C of the condenser. Along thisthis the reflection of the load back into the primary will add to thecombination that makes up the efiective load for the exciting source.The radiation takes place in the area between the variable taps 5.Because the radiation is generated by the inductance, the radiated fieldis primarily of the H component. This is of great value in the RAD-HAZproblem because of the great reduction in generating an electric Efield. The circuit is not limited to a 50 ohm impedence source but willwork well with almost any output termination. The RF ammeter is usedonly to indicate when the circuit is operating at its peak efiiciency.By dipping a VSWR meter and maximizing the LC RF ammeter, it will beeasy to adjust for proper frequency and maximum current. If the systemwere matching a one ohm load the ratio of current would be 7. Thus forevery ampere in the feed line 7 amperes would appear in the circuitammeter. It is in this manner that the circuit is adjusted and by directcomparison will perform as any antenna of the conventional style.

The wave propagated from the antenna of this invention is predominantlyone containing the H component. This is due by generating largesecondary currents through transformer action. The antenna circuitrymatches the feed line impedance to a very low secondary resistance,accounting for the large currents. The antenna can be constructed toradiate on all frequencies by proper selection of the antenna componentsfor the desired frequency range.

What is claimed is:

1. An antenna structure adapted for connection to an input circuitcomprising:

an inductance having a predetermined number of turns connected acrosssaid input circuit;

a pair of adjustable output taps in electrically adjustable relationshipwith said inductance;

a variable capacitor electrically connected across said pair ofadjustable taps;

said inductor and capacitor solely comprising the active radiatingantenna element.

References Cited UNITED STATES PATENTS 1,092,294 4/1914 Schiessler343-850 X 2,650,304 8/1953 Schlesinger 343--743 2,855,599 10/1958Kandoian 343861 2,860,340 11/1958 Barret et a1. 343850 X 1,868,7957/1932 Hansel] 343--865 3,078,348 2/1963 McIntosh 179-82 3,179,941 4/1965 Harris et a1. 343-895 FOREIGN PATENTS 676,743 12/ 1963 Canada.

ELI LIEBERMAN, Primary Examiner.

